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<br />The calculated transmissivity value is 0.03 FT2/Day (0.224 gallons per day <br />per feet2). Using this value, it is estimated by the applicant that ground <br />water effects will not be observed more than 500 feet away from mining. The <br />Division assumes that the transmissivity is actually somewhat greater than <br />that calculated at the well, but is probably variable. <br />The Division projects that inflows in excess of 57.2 gallons per day will be <br />measured at each Pit, and that the effects of mining on the local ground water <br />regime will be felt farther away than 500 feet from the pits. This assumption <br />is based upon transmissivity and storativity values of the Mesaverde Formation <br />throughout Western Colorado. <br />As a general rule, transmissivity and storativity values of the middle to <br />upper Mesaverde, as reported by various mines in western Colorado, are low. <br />However, a value as low as that reported from the Seneca II-W Mine site has <br />not been documented elsewhere. The values calculated at the particular <br />aquifer test site are probably good for that test site, however, the Division <br />must assume that these aquifer characteristics are aerially variable. <br />Therefore, the actual storativity and transmissivity values for the Wadge coal <br />as a unit are probably greater then those reported. <br />The Division's PHC findings are based on greater inflows than those predicted <br />by the applicant. The Williams Fork Formation overburden which locally <br />contains the Lennox Coal Seam, may contain perched aquifers as well as acting <br />as a limited aquifer system near the Wadge coal. The overburden does not <br />contain or transport significant amounts of water in this area. <br />The applicant states that no hydrologic effects due to mining will be noticed <br />at Temple Well No. 1 (a domestic water right), a little south and west of the <br />mine site. Eventually, some effects will be seen at this well. The effects <br />may be exhibited as increased levels of dissolved solids or other chemical <br />parameters (sulphur, iron) and/or diminished quantity of water at the well. <br />These effects will probably not be seen until a number of years after mining <br />has reached its closest point to the well, Eventually, effects will diminish <br />as the dissolved solids are leached from the spoils, and the aquifer <br />characteristics return to normal. <br />Locally, the major impacts of mining include effecting the quantity and/or <br />quality of Springs S-1, S-5, 5-23, 5-25, S-41, 5-45 and S-51. Effects of <br />mining at these sites will not be observed for a few years after mining is at <br />its closest to these points. <br />The Olson Spring (5-45), located about 9,000 feet downgradient of mining, <br />could potentially be impacted. This spring, which issues from the Dry Creek <br />alluvium, could suffer a degradation in water quality. This would occur if <br />the Hubberson Gulch and Dry Creek alluvium are recharged by the spoils aquifer <br />discharge. As will be discussed in the Surface Water section of the <br />Probable Hydrologic Consequences Assessment, this discharge will be of very <br />poor quality. If the quality of Olson Spring, a domestic water right, is <br />affected, the applicant will be responsible for replacing this impacted water <br />with domestic quality water in the aajudicated quantities. <br />-33- <br />